JPH07103135B2 - Dihydrocarbyl dithiophosphyl dithiophosphoric acid metal salt, its production method and its use as a lubricant - Google Patents

Description

FIELD OF THE INVENTION The present invention relates to dihydrocarbyl dithiophosphyl dithiophosphoric acid which can be used as antioxidants, antiwear agents, extreme pressure additives and anticorrosion agents, especially for lubricating oils. Metal salt type compounds,
It relates to a method for producing these compounds and a lubricant containing them.

PRIOR ART Dialkyl and diaryl dithiophosphoric acid metal salts, especially those of zinc, are very widely used for the protection of metal surfaces in the old friction state from wear and corrosion and to the protection of lubricating oils containing them from oxidation. It is used.

For example, U.S. Patent Nos. 2,364,283, 2,364,284, and
Details of the production of such additives can be found in 2,365,938, 2,410,650, 2,438,876 and 3,190,833.

The dialkyl and dialkylaryl dithiophosphoric acid metal salts described in the prior art are generally characterized by a metal / P / S atom ratio of 1/2/4, for example U.S. Pat.
The proportion of sulfur may be higher as a result of the additional sulfurization, as described in 8,876. For effective protection against wear, these substances should be
Generally, it should be used in an amount of 0.5 to 1.5% by weight.

In addition, from German Patent No. 948,156, the thiolthionophosphoric acid (or dithiophosphoric acid) diester is reacted with ethylene oxide to form a thionthionophosphoric acid triester having an oxygenating group and then the product is converted to phosphorus pentasulfide. It has been found that a derivative of thiolthionophosphoric acid can be obtained by treatment with.

These derivatives have various metals (alkali, alkaline earth,
Although it has been pointed out that salts are likely to form, either with heavy metals) or with amines, only the preparation of salts of oleylamine is actually described.

The object of the present invention is in particular similar to the protection by additives of the prior art, but with the metal dithios, such as protection against wear under substantially worse conditions or better protection at the same concentration. It is to provide a novel compound of the phosphate type.

Structure of the Invention The metal salt of dihydrocarbyl dithiophosphyl dithiophosphate of the present invention is a complex compound represented by the following general formula (I): In the formula, R may be the same or different and represents a linear or branched alkyl group having up to 8 carbon atoms or an alkylaromatic group having up to 18 carbon atoms. For example, R
Examples thereof include 1-methylpropyl, 1,3-dimethylbutyl, 1-methylheptyl, butyl and dodecylphenyl groups.

X represents a hydrogen atom and Y represents a methyl group. M represents a metal selected from zinc, admium and lead, and zinc is preferable. n has a valence of 2 of the metal M.

The radical R is generally derived from monohydroxyl compounds, such as substituted or unsubstituted monoalcohols or monophenols.

The substituents X and Y are epoxide reactants used for the synthesis of the products of the invention described below. Derived from.

The metal M in the compound of the present invention is a divalent metal, and the atomic ratio of each of metal, phosphorus and sulfur is about 1/6/12.

The metal dithiophosphates of the present invention may be prepared by a method which essentially comprises the steps of:

In step (a), the so-called "first generation" dithiophosphoric acid is first prepared by the reaction of a hydroxyl compound (substituted or unsubstituted alcohol or phenol) with phosphorus pentasulfide.

The reaction is shown by the following chemical reaction formula.

In the formula, R is the same as above.

The hydroxyl compound which can be used is a ROH compound corresponding to the above R, for example, an aliphatic monoalcohol such as methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol and octanol; and an alkyl aromatic hydroxyl compound.
For example, dodecylphenol or the like can be used.

It should be understood that a mixture of two or more hydroxyl compounds thus defined can be used in this step.

The reaction of one or more hydroxyl compounds with phosphorus pentasulfide is generally as in the prior art, i.e.
It is carried out at 180 ° C, preferably 50-150 ° C. The reactant is
Used in proportions near or close to stoichiometry.

In the second step (b), the product (II) obtained in step (a) is reacted with a compound having an epoxide functional group and propylene oxide.

The reaction is represented by the following chemical reaction formula (2).

In the formula, R, X and Y are the same as above.

Reaction formula (2) relates to the β-hydroxyalkylation reaction of the compound of formula (II). This yields a hydroxyl compound of formula (III), which is a dithiophosphate alcohol.

This reaction generally has a temperature of 0 to 150 ° C, preferably 20 to 130 ° C.
And the reactants are used in a proportion corresponding to or close to stoichiometry.

In the third step (c), dithiophosphate alcohol (II
I) and phosphorus pentasulfide are reacted according to the reaction formula represented by the following chemical reaction formula (3).

In the formula, R, X and Y have the same meaning as described above.

The so-called "secondarily generated" dithiophosphyl dithiophosphoric acid (formula (IV)) is obtained.

The reaction is generally carried out at a temperature of 20-120 ° C, preferably 40-90 ° C, the relative amounts of the reactants being close to stoichiometric.

In the fourth step (d), dithiophosphoric acid (IV) in the form of an alkali metal salt or ammonium salt is reacted with the salt of the desired metal M for the final product. The reaction is represented by the following chemical reaction formula (4).

In the formula, R, X, Y, M and n have the same meaning as described above.

M ₁ is an alkali metal or ammonium, Z is MZn
Represents one equivalent of salt anion. Therefore, Z may be a halogen atom (chlorine or bromine), a nitrate or carboxylate (acetate, formate) group, or a half group such as carbonate or sulfate.

Generally in an aqueous medium, 0-100 ° C, preferably 40-6
Operate at a temperature of 0 ° C. The MZn metal salt is used in excess.

According to the second method for synthesizing the product of the present invention, the product (III) (dithiophosphoric acid alcohol) obtained in the step (b) is directly mixed with phosphorus pentasulfide and the oxide or hydroxide of the desired metal M. To produce the desired metal salt of dihydrocarbyl dithiophosphyl dithiophosphoric acid represented by the following general formula.

The metal M can be selected from zinc, cadmium and lead as described above. Similarly in this reaction,
Hydrogen sulfide and water are formed.

The reaction is generally carried out at 40-100 ° C., preferably 60-90 ° C., in the presence of a solvent capable of removing the water formed by azeotropic entrainment. The preferred solvent is benzene.

The products according to the invention, which may be described as dihydrocarbyl dithiophosphyl dithiophosphoric acid metal salts, are preferably inorganic, especially for protecting metallic equipment from wear and corrosion and to protect lubricating oils from oxidation. And / or can be used as an additive for synthetic lubricating oils.

These additives can generally be used in weight concentrations of 0.05 to 2%, but their main advantage lies in their high antiwear activity. This makes it possible to use them in concentrations of 0.05 to 1% with completely satisfactory effects.

Examples The following examples illustrate the invention but should not be considered in any way limiting. Example 10 was listed as a comparative example.

Example 1 2210 g (29.8 mol) of 2-butanol are introduced into a 5 l reactor equipped with a stirrer and purged with nitrogen. Using an external heating device, bring the alcohol temperature to approximately 90 ° C,
Then, the reaction temperature was set to 90-
While maintaining the temperature at 95 ° C, add P ₂ S _{5 in} stirred alcohol.
1490 g (6.7 mol) are introduced in 2 hours. The reaction is then continued for another 2 hours at 95-100 ° C. to reach complete reaction of P ₂ S ₅ .

A stream of nitrogen is then introduced into the (first-generation) dialkyldithiophosphoric acid for 0.5 hour at 95-100 ° C to remove hydrogen sulfide in the solution and the acid is cooled at 25-30 ° C. A bromine flask connected to the reactor maintained the reaction temperature at 30-35 ° C, and 810 g of propylene oxide (13.9
5 mol) is introduced.

The reactor is then subjected to a reduced pressure of 2666 Pa, while simultaneously heating the dithiophosphoric alcohol obtained at 100 ° C. Under these conditions excess 2-butanol and propylene oxide are removed by distillation.

After cooling, 25 g of filter agent (diatomaceous earth) is added and filtration is performed. In this way 3375 g of dithiophosphoric acid alcohol are recovered.

240 g (0.8 mol) of the dithiophosphoric alcohol previously obtained are introduced into a first reactor equipped with a stirrer and under nitrogen purge, which is then heated to 95.degree.

While maintaining the temperature around 95 ° C. with a powder introducing device, 37 g (0.166 mol) of P ₂ S ₅ was gradually added to the mixture under stirring for 2 hours. The reaction solution is cooled and filtered in the presence of diatomaceous earth under an inert atmosphere to recover 209 g of the acid generated in the second generation (acidity = 1.556 10 ^-3
Acid equivalent / g).

The acid is neutralized with a solution of 13 g sodium hydroxide in 300 cm ^{3 of} water. The milky solution obtained is extracted three times with 500 cm ³ of hexane to remove excess dithiophosphoric acid alcohol and part of the partially soluble sodium salt of the acid.

A (lower) aqueous solution containing the purified sodium salt of the acid was stirred for 3 hours in 150 cm ³ of water with zinc heptahydrate ZnSO ₄ .7H ₂
Treat with a solution of 60 g O2 (0.21 mol).

The milky suspension obtained is extracted 3 times with 300 cm ³ of benzene. The collected benzene extracts are washed with water, dried over anhydrous sodium sulfate, filtered through diatomaceous earth and then under reduced pressure.
Evaporate to constant weight at 0 ° C.

90 g of a very viscous translucent organic product are recovered. Characteristic absorption band of zinc dialkyldithiophosphate, especially 970 cm
^-1 (depending on the group P-O-C from the secondary alcohol), 665c
The composition is confirmed by elementary analysis (Table 1) and NMR13C, 1H, as well as the infrared analysis shown at m ^-1 (by group P = S) and 545 cm ^-1 (by group P-S). These absorption bands are more than those of the corresponding conventional zinc di-sec-butyl dithiophosphates, especially the bands P = S and P.
Significantly stronger is observed for -S.

The product obtained corresponds to the structural formula:

Example 2 "Second generation" prepared from 240 g of dithiophosphorus alcohol
Aqueous solution of purified sodium salt of dithiophosphoric acid in 150 cm ^{3 of} water
The experiment of Example 1 is carried out again by reacting with 79.6 g of lead trihydrate lead acetate Pb (OOCCH ₃ ) ₂ .3H ₂ O dissolved therein. About 100 g of organic product after treatment is recovered. Elemental analysis of this (Table 1), NM
R13C, 1H analysis and infrared analysis give the following structural formula: To confirm.

Example 3 The experiment of Example 3 is repeated by reacting 56 g (0.21 mol) of cadmium acetate dihydrate Cd (OOCCH ₃ ) ₂ .2H ₂ O. Product 80
Collect g. The elemental analysis (Table 1), NMR13C, 1H analysis and infrared analysis are as follows: To confirm.

Example 4 200 g of dithiophosphoric acid alcohol prepared in Example 1 in an inert atmosphere in one reactor equipped with a stirrer, a DEAN-STARCK separator equipped with a cooler and a device for introducing powdered reactants.
(0.66 mol), benzene 300 cm ³ and ZnO 2 0.3 g (0.25 mol) are introduced.

The resulting suspension is heated with stirring to reflux of benzene. The temperature of the medium is 85 to 90 ° C.

36.7 g (0.165 mol) of P ₂ S ₅ are gradually added in 3 hours via a powder reactant introduction device. A "secondary generation" acid is formed. This is reacted with ZnO. The water resulting from the reaction is removed by hetero-azeotropic entrainment by the DEAN-STARCK separator as soon as it is formed. Reflux for a further 3 hours, then allow to cool.

The benzene solution is then filtered in the presence of diatomaceous earth and then evaporated at 100 ° C. under reduced pressure until constant flow rate.

225 g of viscous product are thus recovered. This elemental analysis (Table II), NMR13C, 1H analysis and infrared analysis confirm the following structure. Ie Example 5 4-methyl-2-pentanol 224.4 g (2.2 mol) P ₂ S ₅ 1
The experiment of Example 4 is repeated using 11.1 g (0.5 mol).
The "first generation" acid formation temperature is 85-90 ° C.

After removing dissolved H ₂ S by bubbling nitrogen stream, 30 ~ 35 ℃
The acid is converted to the dithiophosphoric acid alcohol by adding 60.9 g (1.05 mol) of propylene oxide. Excess alcohol and propylene oxide are removed by heating at 100 ° C. under reduced pressure.

Then add 400 cm ^{3 of} benzene and 25 g of ZnO (0.31 mol),
The mixture is brought to reflux (87-90 ° C) with stirring. Then P ₂ S ₅ 5
3.3 g (0.24 mol) are gradually introduced in 3 hours. The water of reaction is gradually entrained by the heteroazeotropic effect of the solvent.

After a further 3 hours of reflux and filtration and evaporation, 367 g of a translucent viscous product are obtained. Elemental analysis of this (table
II), NMR13C, 1H analysis and infrared analysis confirm the following structural formula. That is, Example 6 The experiment of Example 4 is repeated using 286 g (2.2 mol) of 2-octanol, 111.1 g (0.5 mol) of P ₂ S ₅ and 60.9 g (1.05 mol) of propylene oxide. The "first generation" acid formation temperature is fixed at 115-120 ° C.

After removal of excess reactants and dissolved H ₂ S, the mixture is cooled by method, then 400 cm ^{3 of} benzene, 25 g of ZnO (0.31 mol) are added and refluxed. Next, 52.7 g (0.237 mol) of P ₂ S ₅ was added over 3 hours, and the reaction was continued for another 4 hours. The water of reaction is constantly removed.

After cooling, filtration on diatomaceous earth and evaporation under reduced pressure, 432 g of a translucent viscous product are recovered. Elemental analysis of this (Table II),
NMR13C, 1H analysis and infrared analysis confirm the following structural formula. That is, Example 7 Dodecylphenol 262.44 g (1 mol), P ₂ S ₅ 52.78 g
The experiment of Example 5 is repeated with (0.2375 mol). The formation temperature of the "first generation" dithiophosphoric acid is 145 to 155 ° C.

By bubbling nitrogen, after removal of dissolved H ₂ S, 30 to 3
At 5 ° C., the acid is converted to the dithiophosphoric acid alcohol by addition of 28.93 g (0.5 mol) of propylene oxide. Excess propylene oxide is removed by heating at 100 ° C. under reduced pressure.

400 cm ^{3 of} benzene, 38.7 g of ZnO (0.475 mol) are then added to the mixture and the mixture is then brought to reflux.

Then 7.23 g (0.119 mol) of P ₂ S ₅ are gradually introduced in 3 hours. The water of reaction is constantly removed by the hetero-azeotropic entrainment.

After a further 3 hours at reflux and filtration on diatomaceous earth and evaporation under reduced pressure, 332 g of product are recovered. Its elemental analysis (Table II), NMR13C, 1H analysis and infrared analysis
Check the following structural formula. That is, Example 8 81.4 g (1.1 mol) of n-butanol and 14 of 2-octanol
The experiment of Example 4 is repeated using a mixture with 3 g (1.1 mol), P ₂ S ₅ 111.1 g (0.5 mol), propylene oxide 60.9 g (1.05 mol) and ZnO 25 g (0.31 mol). The "first generation" acid formation temperature is fixed at 115 ° C. The preparation of the desired product continues under the conditions of Example 6.

325 g of a translucent viscous product are recovered. This elemental analysis (table
II), NMR13C, 1H analysis and infrared analysis confirm the following structural formula. That is, This formula is a general formula representing a mixture of products containing similar proportions of groups derived from n-butanol and 2-octanol.

Example 9 The experiment of Example 7 is repeated, substituting the same molar amount of ethylene oxide for propylene oxide. At the end of the experiment, the product 31
Collect 4g. The elemental analysis of this is as follows.

In addition, NMR13C, 1H analysis and infrared analysis confirm the following structural formula. That is, Example 10 (Comparative) Similarly, an amine salt corresponding to the teachings of West German Patent No. 948,156 was prepared as follows.

In a 0.5 l reactor, 100 g of a so-called "secondary generation" acid (acidity = 1.55610 ³ acid equivalent / g) is prepared according to the method described in Example 1.

Add 41.6 g of oleylamine, the stoichiometric amount needed to neutralize the acid. After the exothermic reaction, the mixture is heated for 3 hours to complete the reaction.

After filtration 127 g of product are recovered. Elemental analysis of this shows the following P, S and N contents.

Measured value Theoretical value P wt% 9.25 9.66 S 〃 20.52 20.00 N 〃 1.45 1.46 This confirms the structural formula of the oleylamine salt represented by the formula below.

Example 11: TestingThe antiwear properties of the additives whose manufacturing methods are described in the above examples are shown in Peugeot Engine XL with a camshaft overhead.
Clarified using 5.

The equipment used for the test consisted of the two cylinder heads of a Peugeot Engine XL5 mounted on a support that allowed the circulation of oil in the system. The camshaft is pulled directly to the end by an electric motor at two speeds. The system of oil pumps can restore complete motor normal state as well as circuit pressurization before moving the camshaft. Fine filtration (substantially 10 μm) can remove most of the particles formed during rubbing.

The main test conditions are as follows.

・ Rotation speed: 1 minute 750 rotations / minute 2 minutes 1500 rotations / minute ・ Time: 50 hours ・ Oil temperature: 50 ℃ ・ Valve rocker supply pressure: 50 ℃ 2 bar ・ Maximum opening force: 1200N・ Intermediate play adjustment: 25 hours ・ Pressurize and heat the camshaft before starting the drive engine.

After testing, the wear of the valve rockers is averaged (average wear of 16 valve rockers) to evaluate the wear resistance of the additive.

The lubricating oils used are neutral solvent inorganic oils including:
Consists of 175.

Cleaning Additive 3.35 wt% (Ca = 1800 ppm) Ashless Dispersion Additive 5 wt% A series of three experiments was performed. One of them is zinc dithiophosphate of Example 1 (Zn / P / S = 1 / 5.85 / 12.32), the second is the oleylamine salt of Example 10, and the third is Is performed using a conventional zinc dithiophosphate (Zn / P / S = 1/2/4) obtained from 2-butanol. The results obtained are summarized in Table III below.

Examining Table III, in the case of one of the additives of the present invention, than in the case of conventional zinc dithiophosphate obtained from the same initial alcohol, and of the product of the reaction of oleylamine on the secondary evolution of dithiophosphate. In some cases, higher antiwear activity becomes apparent.

In fact, in the case of commercial dithiophosphates, and in the case of amine dithiophosphates, the protection of the valve rocker against wear is
It decreases constantly when the phosphorus content of the lubricant decreases, especially when the phosphorus content is below about 1500 ppm. On the contrary, it can be seen that with one of the products according to the invention, this protection is ensured even at phosphorus contents as low as about 160 ppm.

The same experiments carried out from the same molar amounts of the additives of Examples 2-9 lead to similar results.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location C10N 30:10 30:12 (72) Inventor Pierre Marchamps Orgeval, France (78630) Du Doc Tour Morelle 24-2 (72) Inventor Guy Parc France Rueil Malmaison (92500) Rue du Chateau 27 (72) Inventor Nicole Thevenin Paris (75017) Boulevard France 96 Le Batiniyor

Claims (9)

[Claims] 1. A general formula: (In the formula, R represents a linear or branched alkyl group having up to 8 carbon atoms or an alkyl aromatic group having up to 18 carbon atoms, X represents a hydrogen atom, and Y represents a methyl group. M represents a metal selected from zinc, cadmium and lead, and n
Is 2. ) A compound of dihydrocarbyl dithiophosphyl dithiophosphoric acid metal salt type represented by: 2. R 1 is selected from the group consisting of 1-methylpropyl, 1,3-dimethylbutyl, 1-methylheptyl, butyl, and dodecylphenyl groups. The described compound. 3. A compound as claimed in claim 1 or 2, characterized in that M represents zinc. 4. The atomic ratio of the metal M, phosphorus and sulfur in the compound is about 1/6/12.
The compound according to any one of claims 1 to 3. 5. A hydroxyl compound ROH is reacted with phosphorus pentasulfide to give a compound of the general formula (In the formula, R represents a linear or branched alkyl group having up to 8 carbon atoms or an alkylaromatic group having up to 18 carbon atoms.) (A) ); The dithiophosphoric acid obtained in step (a) is replaced with a compound having an epoxide functional group. By reacting with the general formula (In the formula, X represents a hydrogen atom and Y represents a methyl group.) Step (b) for forming a dithiophosphoric acid alcohol; The dithiophosphoric acid alcohol obtained in the step (b) is reacted with phosphorus pentasulfide. , General formula (In the formula, R, X and Y have the same meanings as described above.) Step (c) for forming dithiophosphyldithiophosphoric acid; and dithiophosphyldithiophosphoric acid obtained in step (c) In the form of an alkali metal or ammonium salt with a salt of the metal M to give a compound of the general formula (In the formula, R, X and Y have the same meanings as described above, M represents a metal selected from zinc, cadmium and lead, and n
Is 2. ) The method for producing a dihydrocarbyl dithiophosphyl dithiophosphoric acid metal salt, which comprises the step (d) of forming a compound represented by: 6. A hydroxyl compound ROH is reacted with phosphorus pentasulfide to give a compound of the general formula (In the formula, R represents a linear or branched alkyl group having up to 8 carbon atoms or an alkylaromatic group having up to 18 carbon atoms.) (A) ); The dithiophosphoric acid obtained in step (a) is replaced with a compound having an epoxide functional group. By reacting with the general formula (In the formula, X represents a hydrogen atom and Y represents a methyl group) in the step (b) of forming a dithiophosphoric acid alcohol; and the dithiophosphoric acid alcohol obtained in the step (b) is converted into phosphorus pentasulfide with a metal. M in the presence of an oxide or hydroxide of the general formula (In the formula, R, X and Y have the same meanings as described above, M represents a metal selected from zinc, cadmium and lead, and n
Is 2. ) The method for producing a metal salt of dihydrocarbyl dithiophosphyl dithiophosphoric acid, which comprises the step (c) of forming a compound represented by: 7. A process according to claim 6, characterized in that step (c) is carried out in the presence of a solvent capable of azeotropically removing the water formed. 8. Inorganic or synthetic lubricating oil is contained in a medium ratio, and the general formula: (In the formula, R represents a linear or branched alkyl group having up to 8 carbon atoms or an alkyl aromatic group having up to 18 carbon atoms, X represents a hydrogen atom, and Y represents a methyl group. M represents a metal selected from zinc, cadmium and lead, and n
Is 2. ) A lubricant composition comprising a dihydrocarbyl dithiophosphyl dithiophosphoric acid metal salt type compound represented by the formula (1) in a proportion of 0.05 to 2% by weight. 9. Composition according to claim 8, characterized in that said proportion is between 0.05 and 1% by weight.